Photoluminescent panel, photoluminescent liquid crystal display device, and method of manufacturing the photoluminescent panel

ABSTRACT

A photoluminescent panel includes a lower substrate, an upper substrate facing the lower substrate, a liquid crystal layer disposed between the lower substrate and the upper substrate, and a color conversion layer disposed on the upper substrate. The color conversion layer includes a light excitation particle which absorbs light having a desired wavelength and emits excited light, and a scattering particle which scatters the excited light.

This application is a continuation application of U.S. application Ser.No. 13/904,254 filed May 29, 2013, which claims priority to KoreanPatent Application No. 10-2012-0142503, filed on Dec. 10, 2012, and allthe benefits accruing therefrom under 35 U.S.C. §119, the contents ofwhich in its entirety is herein incorporated by reference.

BACKGROUND 1. Field

Exemplary embodiments of the invention relate to a photoluminescentpanel, photoluminescent liquid crystal display device having the same,and a method for manufacturing the photoluminescent panel. Moreparticularly, exemplary embodiments of the invention relate to aphotoluminescent panel, photoluminescent liquid crystal display device,and a method of manufacturing the photoluminescent panel for improvinglight emitting efficiency.

2. Description of the Related Art

Generally, a photoluminescent liquid crystal display apparatus(hereinafter, “PL-LCD”) is a liquid crystal display device whichsubstitutes a color filter pattern and a fluorescent lamp of aconventional liquid crystal display device for a fluorescent pattern andan ultraviolet lamp, respectively. The PL-LCD displays an image using avisible light emitted from a color conversion layer when an outer orexternal light having a short wavelength is illuminated on the colorconversion layer.

SUMMARY

One or more exemplary embodiment of the invention provides aphotoluminescent panel for improving light emitting efficiency.

Another exemplary embodiment of the invention provides aphotoluminescent liquid crystal display device having thephotoluminescent panel.

Yet another exemplary embodiment of the invention provides a method ofmanufacturing the photoluminescent panel.

In an exemplary embodiment of a photoluminescent panel according to theinvention, the photoluminescent panel includes a lower substrate, anupper substrate facing the lower substrate, a liquid crystal layerdisposed between the lower substrate and the upper substrate, and acolor conversion layer disposed on the upper substrate. The colorconversion layer includes a light excitation particle which absorbslight having a desired wavelength and emits excited light, and ascattering particle which scatters the excited light.

In an exemplary embodiment, the color conversion layer may furtherinclude a reflection wall which reflects the excited light.

In an exemplary embodiment, the color conversion layer may furtherinclude a first area in which the light excitation particle is disposedand a second area in which the scattering particle is disposed. Thefirst area may be above the second area.

In an exemplary embodiment, the color conversion layer may furtherinclude a first area in which the light excitation particle is disposedand a second area in which the scattering particle is disposed. Thefirst area may be below the second area.

In an exemplary embodiment, the color conversion layer may furtherinclude a plurality of light excitation particles and a plurality ofscattering particles interspersed with each other within the colorconversion layer.

In an exemplary embodiment, the color conversion layer may furtherinclude a light blocking pattern, and the reflection wall may beextended in a substantially perpendicular direction with respect to alower surface of the light blocking pattern.

In an exemplary embodiment, a cross-sectional side surface of the lightblocking pattern may have a curved or stepped shape, the reflection wallmay contact and cover the cross-sectional side surface of the lightblocking pattern, and an end portion of the reflection wall may beextended in a substantially perpendicular direction with respect to thelower surface of the light blocking pattern.

In an exemplary embodiment, the color conversion layer may furtherinclude a plurality of the light excitation particles emitting differentcolor lights, and the color lights emitted at opposing sides of thereflection wall are different from each other.

In an exemplary embodiment, the light blocking pattern may have a firstwidth at an upper portion thereof and a second width at a lower portionthereof. The first width may be different from the second width.

In an exemplary embodiment, the light blocking pattern may have a tiltedcross-sectional side surface, and the reflection wall may contact andcover the tilted cross-sectional side surface of the light blockingpattern.

In an exemplary embodiment, the color conversion layer may furtherinclude a plurality of light excitation particles emitting differentcolor lights, and the light excitation particles may include at leasttwo materials among a green phosphor, a red phosphor and a yellowphosphor.

In an exemplary embodiment, the color conversion layer may furtherinclude a plurality of light excitation particles emitting differentcolor lights, and the light excitation particle may include at least twomaterials among a green quantum dot, a red quantum dot and a bluequantum dot.

In an exemplary embodiment, the scattering particle may include titaniumoxide or silicon oxide.

In an exemplary embodiment of a photoluminescent liquid crystal displaydevice according to the invention, the photoluminescent liquid crystaldisplay device includes a backlight unit which emits light having adesired wavelength, a first substrate disposed on the backlight unit, asecond substrate facing the first substrate and disposed on the firstsubstrate, a liquid crystal layer disposed between the first and thesecond substrates, and a color conversion layer disposed on the secondsubstrate. The color conversion layer includes a plurality of lightexcitation particles which absorbs the light to emit excited lightshaving three different colors, and a scattering particle which scattersthe excited lights.

In an exemplary embodiment, the color conversion layer may furtherinclude a reflection wall which reflects the excited lights and a lightblocking pattern which blocks the excited lights.

In an exemplary embodiment, the reflection wall may be extended in asubstantially perpendicular direction with respect to a lower surface ofthe light blocking pattern.

In an exemplary embodiment, the device may further include an opticalfilter layer between the color conversion layer and the secondsubstrate.

In an exemplary embodiment of a method of manufacturing aphotoluminescent panel according to the invention, the method ofmanufacturing the photoluminescent panel includes providing a lightblocking pattern and a plurality of color areas spaced apart from eachother on a substrate, providing a light excitation pattern on the colorareas to define a gap corresponding to the light blocking pattern whichis between adjacent color areas, providing a reflection member in thegap and on a portion of the light excitation pattern which is exposed bythe gap, and providing a flattening layer on the light excitationpattern and the reflection member. The light excitation pattern includesa light excitation particle which emits excited light having a desiredcolor.

In an exemplary embodiment, the flattening layer may include scatteringparticle which scatters the excited light.

In an exemplary embodiment, the plurality of color areas may include afirst color area, a second color area, and a third color area. Theproviding a light excitation pattern on the color areas may includeproviding a first light excitation pattern on the first color area,providing a second light excitation pattern on the second color area andproviding a third light excitation pattern on the third color area. Thefirst light excitation pattern may include a first light excitationparticle which emits a first excited light having a first color. Thesecond light excitation pattern may include a second light excitationparticle which emits a second excited light having a second color. Thethird light excitation pattern may include a third light excitationparticle which emits a third excited light having a third color.

According to one or more exemplary embodiment of the photoluminescentpanel, the photoluminescent liquid crystal display device, and themethod of manufacturing the photoluminescent panel, excited light from alight excitation particle may be scattered by a scattering particlewithin a color conversion layer to improve light emitting efficiency.

Also, the excited light and scattered light may be reflected upward by areflection wall to improve light emitting efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the invention will becomemore apparent by describing in detailed exemplary embodiments thereofwith reference to the accompanying drawings, in which:

FIG. 1 is a cross-sectional view of an exemplary embodiment of aphotoluminescent liquid crystal display device according to theinvention;

FIG. 2 is a cross-sectional view illustrating an exemplary embodiment ofvisible lights having different wavelengths emitted from thephotoluminescent liquid crystal display device of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of portion ‘A’ of FIG. 2;

FIG. 4 is a graph illustrating luminance distribution of thephotoluminescent panel of FIG. 2 with respect to a light emitting anglein degrees)(°;

FIGS. 5A to 5G are cross-sectional views illustrating an exemplaryembodiment of a method of manufacturing a facing substrate of thephotoluminescent panel of FIG. 1;

FIG. 6 is a cross-sectional view of another exemplary embodiment of aphotoluminescent liquid crystal display device according to theinvention;

FIG. 7 is a cross-sectional view of another exemplary embodiment of aphotoluminescent liquid crystal display device according to theinvention;

FIG. 8 is a cross-sectional view of another exemplary embodiment of aphotoluminescent liquid crystal display device according to theinvention;

FIG. 9 is a cross-sectional view of another exemplary embodiment of aphotoluminescent liquid crystal display device according to theinvention; and

FIG. 10 is a cross-sectional view of another exemplary embodiment of aphotoluminescent liquid crystal display device according to theinvention.

DETAILED DESCRIPTION

The invention is described more fully hereinafter with reference to theaccompanying drawings, in which exemplary embodiments of the inventionare shown. This invention may, however, be embodied in many differentforms and should not be construed as limited to the exemplaryembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the size and relative sizes of layers and regions may beexaggerated for clarity.

It will be understood that when an element or layer is referred to asbeing “on” or “connected to” another element or layer, the element orlayer can be directly on or connected to another element or layer orintervening elements or layers. In contrast, when an element is referredto as being “directly on” or “directly connected to” another element orlayer, there are no intervening elements or layers present. As usedherein, connected may refer to elements being physically and/orelectrically connected to each other. Like numbers refer to likeelements throughout. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another region, layer or section. Thus, a first element,component, region, layer or section discussed below could be termed asecond element, component, region, layer or section without departingfrom the teachings of the invention.

Spatially relative terms, such as “below,” “lower,” “above,” “upper” andthe like, may be used herein for ease of description to describe therelationship of one element or feature to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation, in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” relative to otherelements or features would then be oriented “above” relative to theother elements or features. Thus, the exemplary term “below” canencompass both an orientation of above and below. The device may beotherwise oriented (rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used in thisspecification, specify the presence of stated features, integers,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention. Assuch, variations from the shapes of the illustrations as a result, forexample, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments of the invention should not be construed aslimited to the particular shapes of regions illustrated herein but areto include deviations in shapes that result, for example, frommanufacturing.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

All methods described herein can be performed in a suitable order unlessotherwise indicated herein or otherwise clearly contradicted by context.The use of any and all examples, or exemplary language (e.g., “suchas”), is intended merely to better illustrate the invention and does notpose a limitation on the scope of the invention unless otherwiseclaimed. No language in the specification should be construed asindicating any non-claimed element as essential to the practice of theinvention as used herein.

Hereinafter, exemplary embodiments of the invention will be described infurther detail with reference to the accompanying drawings.

In a conventional liquid crystal display device, an amount of lightemitted from a backlight unit is reduced by about one third (⅓) due to ared color filter, a green color filter and a blue color filter of theconventional liquid crystal display device. To address the reduction inlight, a photoluminescent liquid crystal display (hereinafter, “PL-LCD”)apparatus includes light excitation particles in a color conversionlayer, which emit different color lights. However, most of excitedlights from the light excitation particles in the color conversion layerare totally reflected inward when the excited lights pass through asubstrate or air which covers the color conversion layer. Accordingly,about 10% of original or incident light of the backlight unit is emittedoutward to reduce light emitting efficiency of the PL-LCD.

FIG. 1 is a cross-sectional view of an exemplary embodiment of a PC-LCDdevice according to the invention.

Referring to FIG. 1, an exemplary embodiment of a PL-LCD device 100according to the invention includes a backlight unit 110 and aphotoluminescent panel 120 displaying an image in response to light fromthe backlight unit 110.

The backlight unit 110 emits the light having a desired wavelength suchas ultraviolet waveband or blue light waveband toward thephotoluminescent panel 120. The backlight unit 110 includes a lightsource (not shown) generating and emitting the light having the desiredwavelength. In one exemplary embodiment, for example, the light sourcemay emit light having a wavelength from about 200 nanometers to about400 nanometers. The backlight unit 110 further includes a light guideplate (not shown) guiding the light from the light source to thephotoluminescent panel 120.

The photoluminescent panel 120 includes an array substrate 130, a facingsubstrate 140, and a liquid crystal layer 150 disposed between the arraysubstrate 130 and the facing substrate 140. The photoluminescent panel120 adjusts transmissivity of the light from the backlight unit 110 todisplay an image.

The array substrate 130 includes a first transparent substrate 131, aswitching element 133 disposed on a pixel area of the first transparentsubstrate 131, an insulation layer 135 partially exposing an electrodeof the switching element 133, and a pixel electrode 137 electricallyconnected to an output electrode of the switching element 133 anddisposed on the pixel area. The output electrode of the switchingelement 133 is exposed by the insulation layer 135. The array substrate130 may further include a gate line (not shown) disposed on the firsttransparent substrate 131 and elongated to extend in a first directionand a data line (not shown) disposed on the first transparent substrate131 and elongated to extend in a second direction crossing the firstdirection.

The switching element 133 includes a thin film transistor having asource electrode, a drain electrode and a gate electrode. In oneexemplary embodiment, for example, the thin film transistor may have abottom-gate structure which the gate electrode is disposed at a lowerlayer of the array substrate 130, and the source and the drainelectrodes are disposed at an upper layer of the array substrate 130.Alternatively, the thin film transistor may have a top-gate structurewhich the gate electrode is disposed at the upper layer, and the sourceand the drain electrodes are disposed at the lower layer.

The facing substrate 140 includes a second transparent substrate 141, acommon electrode 143 disposed on a first surface of the secondtransparent substrate 141, a third transparent substrate 145 disposed onan opposing second surface of the second transparent substrate 141 andfacing the second transparent substrate 141, and a color conversionlayer 147 disposed between the second transparent substrate 141 and thethird transparent substrate 145. The facing substrate 140 may furtherinclude an intermediate layer 149 between the second transparentsubstrate 141 and the color conversion layer 147. The facing substrate140 may further include a polarizing film (not shown) between the secondtransparent substrate 141 and the color conversion layer 147.

The second and the third transparent substrates 141 and 145 include atransparent material. In one exemplary embodiment, for example, thesecond and the third transparent substrates 141 and 145 may includeglass or plastic.

The common electrode 143 includes a transparent conductive material. Acommon voltage is applied to the common electrode 143.

The color conversion layer 147 includes a light excitation particle 142,a scattering particle 144 and a reflection wall 146. The lightexcitation particle 142, the scattering particle 144 and the reflectionwall 146 may be disposed within a resin layer. In one exemplaryembodiment, for example, the resin layer may include a silicon resin ora photoresist resin. The color conversion layer 147 may further includea light blocking pattern BM.

The light excitation particle 142 absorbs light having a desiredwavelength to have an excited state. From the excited state, the lightexcitation particle 142 returns to a ground state emitting some amountof light energy. The light excitation particle 142 includes a phosphoror a quantum dot. In one exemplary embodiment, for example, the lightexcitation particle 142 may include oxynitride, nitride, silicate,aluminated, scatdate or oxyfluoride materials.

When the light excitation particle 142 is a phosphor, the lightexcitation particle 142 may be distributed within the color conversionlayer 147 with a concentration of substantially 3 grams per cubiccentimeter to about 4 grams per cubic centimeter. Also, the lightexcitation particle 142 may have a size of substantially 5 micrometersto about 20 micrometers. When a light excitation particle 142G includesa phase of the formula Si6-zLzOzN8-z where L is a Group 13 element suchas Al (e.g., β-SiAlON), (Ba, Sr)2SiO4:Eu or CaSc20:Ce, the lightexcitation particle 142G may emit excited light having a greenwavelength. In one exemplary embodiment, for example, when the phosphoris α-SiAlON, the light excitation particle 142 may be distributed withinthe color conversion layer 147 with a concentration of substantially 3.2grams per cubic centimeter. When a light excitation particle 142Rincludes CaAlSiN3:Eu, (Sr, Ca)AlSiN3:Eu or CaAlSi(ON)3:Eu, the lightexcitation particle 142R may emit excited light having a red wavelength.When a light excitation particle 142B includes Y3Al5O12:Ce orTb3Al5O12:Ce, the light excitation particle 142B may emit excited lighthaving a yellow wavelength. If a blue light is illuminated from thebacklight unit 110 and the light excitation particle 142B includes theY3Al5O12:Ce or Tb3Al5O12:Ce, then a white light may be emitted from thecolor conversion layer 147, when the excited light having the yellowwavelength due to the light excitation particle 142B and the blue lightfrom the backlight unit 110 are mixed.

When the light excitation particle 142 is a quantum dot, the lightexcitation particle 142 may include II-VI type of quantum dots includingCdSe/ZnS, CdSe/CdS/ZnS, ZnSe/ZnS or ZnTe/ZnSe. Alternatively, the lightexcitation particle 142 may include III-V type of quantum dots includingInP/ZnS or a quantum dot including CuInS(2)/ZnS. When the lightexcitation particle 142 is a quantum dot, the light excitation particle142 may be distributed within the color conversion layer 147 with aconcentration of substantially 4 grams per cubic centimeter to about 5grams per cubic centimeter. The light excitation particle 142 may have asize or dimension of substantially lower than about 10 nanometers. Whenthe light excitation particle 142 includes the quantum dot, wavelengthsof excited light from the light excitation particle 142 may bedetermined according to a size or dimension of the quantum dot. In oneexemplary embodiment, for example, the excited light from the quantumdot may be red, green or blue colored light according to the size of thequantum dot. In one exemplary embodiment, for example, when the quantumdot includes CdSe/ZnS, the quantum dot may be distributed within thecolor conversion layer 147 with a concentration of substantially 4.43grams per cubic centimeter.

The scattering particle 144 scatters the excited light emitted from thelight excitation particle 142. The scattering particle 144 may includetitanium oxide or silicon oxide. In one exemplary embodiment, forexample, the scattering particle 144 may include TiO2 or SiO2. Thescattering particle 144 may have a size of substantially lower thanabout 1 micrometer. In one exemplary embodiment, for example, thescattering particle 144 may be distributed within the color conversionlayer 147 with a concentration of substantially 4.23 grams per cubiccentimeter.

The reflection wall 146 reflects the excited light from the lightexcitation particle 142 and/or the excited light scattered by thescattering particle 144. The reflection wall 146 includes a reflectivematerial which reflects visible or ultraviolet lights. In one exemplaryembodiment, for example, the reflection wall 146 may include aluminum.

The light blocking pattern BM is disposed corresponding to boundaries ofa pixel area to block light. The light blocking pattern BM overlaps thegate line and/or the data line. The light blocking pattern BM mayinclude metal or organic materials having a high optical density. In oneexemplary embodiment, for example, the light blocking pattern BM mayinclude chromium.

The intermediate layer 149 includes an optical clean adhesive (“OCA”)film, an optical filter layer or air layer. The intermediate layer 149may reflect the excited light upward toward the third transparentsubstrate 145 when the excited light is scattered or reflected downwardtoward the liquid crystal layer 150 by the scattering particle 144 orthe reflection wall 146, respectively.

FIG. 2 is a cross-sectional view illustrating an exemplary embodiment ofvisible lights having different wavelengths emitted from the PL-LCDdevice of FIG. 1.

Referring to FIG. 2, a first light L1 emitted from the backlight unit110 passes through the array substrate 130 to arrive at the liquidcrystal layer 150. Arrangement of liquid crystals in the liquid crystallayer 150 changes according to voltages applied to the pixel electrode137 and the common electrode 143. An amount of first light L1 passingthrough the liquid crystal layer 150 is adjusted by the alteredarrangement of the liquid crystals. A second light L2 of which an amountthereof is adjusted by the liquid crystal layer 150 arrives at the colorconversion layer 147. The light excitation particle 142 in the colorconversion layer 147 absorbs the second light L2 to have an excitedstate. Excited light is emitted from the light excitation particle 142when the light excitation particle 142 returns to a ground state. Thesecond light L2 passing through the color conversion layer 147 isconverted to a third light L3.

The light excitation particle 142R in a first color area 160R of thecolor conversion layer 147 may emit excited light having red wavelength.The light excitation particle 142G in a second color area 160G of thecolor conversion layer 147 may emit excited light having greenwavelength. The light excitation particle 142B in a third color area160B of the color conversion layer 147 may emit excited light havingblue wavelength. Alternatively, when the first light emitted from thebacklight unit 110 is blue light, white light may be emitted from thethird color area 160B by mixing of the blue light and excited light fromthe light excitation particle 142B in the third color area 160B.

Although the light excitation particle 142B is disposed in the thirdcolor area 160B in FIG. 2, a light excitation particle may not bedisposed in the third color area 160B of the color conversion layer 147when the first light L1 emitted from the backlight unit 110 is bluelight. When the third color area 160B excludes a light excitationparticle, luminance of the blue light emitted through the third colorarea 160B may be controlled solely by the liquid crystal layer 150corresponding to the third color area 160B.

FIG. 3 is an enlarged cross-sectional view of portion ‘A’ of FIG. 2.

Referring to FIG. 1 and FIG. 3, a plurality of light excitationparticles 142 is distributed (e.g., interspersed) in a first depth areaDA1 of the color conversion layer 147. A plurality of scatteringparticles 144 is distributed in a second depth area DA2 of the colorconversion layer 147. The first depth area DA1 may be positioned abovethe second depth area DA2 within the color conversion layer 147. Thelight excitation particles may include at least two materials among agreen phosphor, a red phosphor and a yellow phosphor, but are notlimited thereto or thereby. The light excitation particles may includeat least two materials among a green quantum dot, a red quantum dot anda blue quantum dot, but are not limited thereto or thereby.

When viewed cross-sectionally, the light blocking pattern BM has adesired depth D, and a width taken parallel to the second or thirdtransparent substrates 141 and 145. The light blocking member BM mayhave a first width UW at an upper portion thereof and a second width LWat a lower portion thereof. The first width UW may be substantially thesame as the second width LW as illustrated in FIG. 1. The first width UWmay at the third transparent substrate 145 side of the color conversionlayer 147, while the second width LW may be at the second transparentsubstrate 141 side of the color conversion layer 147.

The reflection wall 146 is adjacent to an outer surface or edge of thelight blocking pattern BM. In one exemplary embodiment, for example, thelight blocking pattern BM may be disposed at an upper portion of thecolor conversion layer 147 and the reflection wall 146 may be adjacentto a lower surface of the light blocking pattern BM. When viewedcross-sectionally, the reflection wall 146 may be elongated in asubstantially perpendicular direction to the lower surface of the lightblocking pattern BM within the color conversion layer 147. Thereflection wall 146 may be spaced apart from a lower boundary of thecolor conversion layer 147.

Hereinafter, a concept which the second light L2 passing through thecolor conversion layer 147 is converted to a third light L3 (e.g.,visible light) which passes through an upper boundary of the colorconversion layer 147 is described in detail.

The second light L2 passing through the liquid crystal layer 150 arrivesat the color conversion layer 147. A portion of the second light L2arriving at the color conversion layer 147 is absorbed by the lightexcitation particle 142 to be emitted as excited light. According toexemplary embodiments, another portion of the second light L2 (such as aremaining portion of the second light L2) which is not absorbed by thelight excitation particle 142 may directly pass through the colorconversion layer 147 to be emitted therefrom.

A portion of the excited light emitted from the light excitationparticle 142 is scattered by the scattering particle 144. Anotherportion (such as a remaining portion) of the excited light emitted fromthe light excitation particle 142 is reflected by the reflection wall146. That is, the third light L3 emitted from the color conversion layer147 includes excited light directly emitted from the light excitationparticle 142, excited light scattered upward by the scattering particle144 and excited light reflected upward by the reflection wall 146.

Also, the third light L3 emitted from the color conversion layer 147 mayinclude excited light which is scattered first by the scatteringparticle 144 and then reflected upward by the reflection wall 146. Also,the third light L3 emitted from the color conversion layer 147 mayinclude excited light which is reflected first by the reflection wall146 and then scattered upward by the scattering particle 144. That is,the third light L3 includes all parts of excited light which is directlyemitted from the light excitation particle 142, scattered and/orreflected by the scattering particle 144 and the reflection wall 146,respectively, and directed upward. The third light L3 may include theportion of the second light L2 which is not absorbed by the lightexcitation particle 142 and which directly passes through the colorconversion layer 147, but the invention is not limited thereto orthereby.

When the intermediate layer 149 is disposed between the color conversionlayer 147 and the second transparent substrate 141, excited lightemitted downward directly from the light excitation particle 142, andexcited light from the light excitation particle 142 which is scatteredand/or reflected downward by the scattering particle 144 and thereflection wall 146 may be re-reflected by the intermediate layer 147 tobe directed upward. Also, the re-reflected excited light may bescattered and/or reflected by the scattering particle 144 and thereflection wall 146 to pass through the upper boundary of the colorconversion layer 147.

As mentioned above, the second light L2 passing through the liquidcrystal layer 150 is converted to the third light L3 having a desiredcolor wavelength by the light excitation particle 142. Then, the lightmay be directly emitted from the light excitation particle 142, and/ormay be scattered and/or reflected upward by the scattering particle 144and the reflection wall 146. Accordingly, light emitting efficiency ofthe photoluminescent panel may be improved.

Table 1 indicates an amount of excited light emitted outward accordingto an existence of a scattering particle 144 when a light excitationparticle 142 includes a quantum dot. As the scattering particle 144,titanium dioxide was used in Table 1. As the quantum dot, a greenquantum dot which emits excited light having a wavelength of about 492nanometers to about 590 nanometers was used. Referring to Table 1, lightemitting efficiency of an exemplary embodiment of the photoluminescentpanel including the scattering particle 144 is increased to about 40%,as compared to a Comparative embodiment which excludes the scatteringparticle.

TABLE 1 Comparative embodiment Exemplary embodiment Scattering particleNone TiO2 layer having 100 nanometer (nm) Light amount of 1.45 × 10⁻⁵2.02 × 10⁻⁵ green excited light [unit: watt per steradian (W/sr)]

FIG. 4 is a graph illustrating luminance distribution of thephotoluminescent panel of FIG. 2 with respect to a light emitting angle.

More particularly, FIG. 4 illustrates relative luminance of thephotoluminescent panel of FIG. 2 with respect to a light emitting anglein degrees)(° when titanium dioxide having a diameter of 2 micrometerswith a concentration of 200 per cubic millimeter is distributed in apolymethyl methacrylate (“PMMA”) resin as the scattering particle of thecolor conversion layer. Light is directed toward the scattering particlein the PMMA resin and scattered light through an upper boundary of thePMMA resin was detected. Referring to FIG. 4, a light emitting angle ofzero (0) represents an area in which the scattering particle is presentwithin the PMMA resin. A positive angle along the horizontal axisrepresents a direction to which the light is directed within the PMMAresin while a negative angle along the horizontal axis represents areverse direction from which the light is directed within the PMMAresin.

Referring to FIG. 4, where the PMMA resin in the color conversion layerfurther includes the reflection wall with the scattering particle,relative luminance in areas in the reverse direction is considerablyincreased compared to a PMMA resin without the reflection wall. Inparticular, luminance at an angle of zero (0) is increased to about 10%,and luminance at minus 40 degrees of light emitting angle is almostdoubled.

As mentioned above, excited light emitted from the light excitationparticle may be scattered and/or reflected by the scattering particleand the reflection wall in the color conversion layer to improve lightemitting efficiency. Also, excited light totally reflected inward at anupper boundary of the color conversion layer and returning to the colorconversion layer may be reduced to improve light emitting efficiency ofthe photoluminescent panel.

FIGS. 5A to 5G are cross-sectional views illustrating an exemplaryembodiment of a method of manufacturing a facing substrate of aphotoluminescent panel, such as the facing substrate 140 of FIG. 1.

Referring to FIG. 5A, a chromium layer is formed (e.g., provided) on thethird transparent substrate 145, and a photoresist is provided on thechromium layer. Then, the photoresist is selectively illuminated anddeveloped using a mask (not shown) to form the light blocking pattern BMin a desired area on the third transparent substrate 145. In a plan viewof the third transparent substrate 145, the light blocking pattern BMmay have substantially lattice shape corresponding to the gate line andthe data line of the array substrate, but is not limited thereto orthereby. The first width UW of the light blocking pattern BM may betaken at a first end thereof adjacent to the third transparent substrate145, and the second width LW may be taken at a distal second end ofthereof, each width being taken substantially parallel to the thirdtransparent substrate 145.

Referring to FIG. 5B, a first light excitation pattern 148R including alight excitation particle 142R which emits excited light having a firstcolor is formed in a first color area 160R on the third transparentsubstrate 145 including the light blocking pattern BM thereon. Moreparticularly, a resin layer including the light excitation particle 142Ris provided on the third transparent substrate 145 including the lightblocking pattern BM thereon, and then the resin layer is selectivelyilluminated and developed to form the first light excitation pattern148R including the light excitation particle 142R which emits excitedlight having the first color in the first color area 160R.

Referring to FIG. 5C, a second light excitation pattern 148G including alight excitation particle 142G which emits excited light having a secondcolor is formed in a second color area 160G on the third transparentsubstrate 145 including the first light excitation pattern 148R thereon.More particularly, a resin layer including the light excitation particle142G is provided on the third transparent substrate 145 including thefirst light excitation pattern 148R and the light blocking pattern BMthereon, and then the resin layer is selectively illuminated anddeveloped to form the second light excitation pattern 148G including thelight excitation particle 142G which emits excited light having thesecond color in the second color area 160G. Also, a first gap GA1 isdefined between the first light excitation pattern 148R and the secondlight excitation pattern 148G. The first gap GA1 is disposedcorresponding to and overlapping the light blocking pattern BM betweenthe first light excitation pattern 148R and the second light excitationpattern 148G. Furthermore, a portion of side surfaces of the first lightexcitation pattern 148R and the second light excitation pattern 148Gfacing each other, is exposed by the first gap GA1.

Referring to FIG. 5D, a third light excitation pattern 148B including alight excitation particle 142B which emits excited light having a thirdcolor is formed in a third color area 160B on the third transparentsubstrate 145 including the second light excitation pattern 148Gthereon. More particularly, a resin layer including the light excitationparticle 142B is provided on the third transparent substrate 145including the light blocking pattern, the first light excitation pattern148R and the second light excitation pattern 148G thereon, and then theresin layer is selectively illuminated and developed to form the thirdlight excitation pattern 148B including the light excitation particle142B which emits excited light having the third color in the third colorarea 160B. Also, a second gap GA2 is defined between the second lightexcitation pattern 148G and the third light excitation pattern 148B. Thesecond gap GA2 is disposed corresponding to and overlapping the lightblocking pattern BM between the second light excitation pattern 148G andthe third light excitation pattern 148B. Furthermore, a portion of sidesurfaces of the second light excitation pattern 148G and the third lightexcitation pattern 148B facing each other, is exposed by the second gapGA2. A third gap GA3 is defined between the third light excitationpattern 148B and the first light excitation pattern 148R. The third gapGA3 is disposed corresponding to and overlapping the light blockingpattern BM between the third light excitation pattern 148B and the firstlight excitation pattern 148R. Furthermore, a portion of side surfacesof the third light excitation pattern 148B and the first lightexcitation pattern 148R facing each other, is exposed by the third gapGA3.

Although the light excitation patterns 148R, 148G and 148B are formed ina sequence of red, green and blue in FIGS. 5B to 5D, the sequence inwhich the light excitation patterns 148 are formed may be various. Also,although the first light excitation pattern 148R including the lightexcitation particle 142R which emits excited light having the firstcolor, the second light excitation pattern 148G including the lightexcitation particle 142G which emits excited light having the secondcolor, and the third light excitation pattern 148B including the lightexcitation particle 142B which emits excited light having the thirdcolor were sequentially formed in FIGS. 5B to 5D, the light excitationpatterns 148 may be formed as a process that a resin pattern without thelight excitation particles 142 is formed on the third transparentsubstrate 145 and then the light excitation particles 142R, 142G, 142Bmay be injected to the resin pattern corresponding to each color areas.

Referring to FIG. 5E, the reflection wall 146 is formed on the facingside surfaces of the light excitation patterns 148 which are exposed bythe first gap GA1, the second gap GA2 and the third gap GA3. Thereflection wall 146 may be formed at the first, the second and the thirdgaps GA1, GA2 and GA3 to totally fill or partially fill each of the gapsGA1, GA2 GA3. In one exemplary embodiment, for example, a reflectionlayer may be formed on the light excitation patterns 148 and the lightblocking pattern BM using methods such as physical vapor deposition(“PVD”), chemical vapor deposition (“CVD”) or electroplating. Then anetch mask may be provided corresponding to the gaps GA1, GA2 and GA3 toform the reflection wall 146 by etching the reflection layer.Alternatively, the reflection layer may be anisotropcially dry etchedcorresponding to the gaps GA1, GA2 and GA3 to form the reflection wall146. Accordingly, the reflection wall 146 having a desiredcross-sectional shape may be formed in a portion or whole of the gapsGA1, GA2 and GA3.

The cross-sectional shape of the reflection wall 146 may be variousaccording to exemplary embodiments. In the exemplary embodiment of FIGS.5E to 5G, for example, the cross-sectional shape of the reflection wall146 is substantially linear and perpendicular to a surface of the lightblocking pattern BM.

Referring to FIG. 5F, a flattening layer FL is formed on the thirdtransparent substrate 145 including the light excitation patterns 148thereon. The flattening layer FL includes the scattering particle 144therein. The flattening layer FL may include substantially the samematerial as the light excitation patterns 148. According to alternativeexemplary embodiments, the flattening layer FL may further include lightexcitation particles 142 which emit different color lights correspondingto each of the color areas 160. The light excitation particles mayinclude at least two materials among a green phosphor, a red phosphorand a yellow phosphor, but are not limited thereto or thereby. The lightexcitation particles may include at least two materials among a greenquantum dot, a red quantum dot and a blue quantum dot, but are notlimited thereto or thereby.

Referring to FIG. 5G, the third transparent substrate 145 including theflattening layer FL therein is assembled with a first surface of thesecond transparent substrate 141, and a common electrode layer 143 isformed on an opposing second surface of the second transparent substrate141. According to exemplary embodiments, a polarizing film, an opticalfilm layer or an OCA film may be disposed between the second and thethird transparent substrates 141 and 145.

FIG. 6 is a cross-sectional view of another exemplary embodiment of aPL-LCD device according to the invention.

Referring to FIG. 6, an exemplary embodiment of a PL-LCD device 200according to the invention includes a backlight unit 110 and aphotoluminescent panel 120 displaying an image in response to light fromthe backlight unit 110. The exemplary embodiment of the PL-LCD device200 according to the invention is substantially the same as the PL-LCDdevice 100 of FIG. 1 except for a location of depth areas DA1 and DA2 inwhich a plurality of light excitation particles 142 and a plurality ofscattering particles 144 is distributed (e.g., interspersed) within acolor conversion layer 147.

The backlight unit 110 emits the light having a desired wavelength suchas ultraviolet waveband or blue light waveband toward thephotoluminescent panel 120. The backlight unit 110 includes a lightsource (not shown) generating and emitting the light having the desiredwavelength.

The photoluminescent panel 120 includes an array substrate 130, a facingsubstrate 140, and a liquid crystal layer 150 disposed between the arraysubstrate 130 and the facing substrate 140. The photoluminescent panel120 adjusts transmissivity of the light from the backlight unit 110 todisplay an image.

The array substrate 130 includes a first transparent substrate 131, aswitching element 133 disposed on a pixel area of the first transparentsubstrate 131, an insulation layer 135 partially exposing an electrodeof the switching element 133, and a pixel electrode 137 electricallyconnected to an output electrode of the switching element 133 anddisposed on the pixel area.

The facing substrate 140 includes a second transparent substrate 141, acommon electrode 143 disposed on a first surface of the secondtransparent substrate 141, a third transparent substrate 145 disposed onan opposing second surface of the second transparent substrate 141 andfacing the second transparent substrate 141, and a color conversionlayer 147 disposed between the second transparent substrate 141 and thethird transparent substrate 145. The facing substrate 140 may furtherinclude an intermediate layer 149 between the second transparentsubstrate 141 and the color conversion layer 147. The facing substrate140 may further include a polarizing film (not shown) between the secondtransparent substrate 141 and the color conversion layer 147.

The color conversion layer 147 includes a light excitation particle 142,a scattering particle 144 and a reflection wall 146. The lightexcitation particle 142, the scattering particle 144 and the reflectionwall 146 may be disposed within a resin layer. In one exemplaryembodiment, for example, the resin layer may include a silicon resin ora photoresist resin. The color conversion layer 147 may further includea light blocking pattern BM.

The light excitation particle 142 absorbs light having a desiredwavelength to have an excited state. From the excited state, the lightexcitation particle 142 returns to a ground state emitting some amountof light energy. The light excitation particle 142 includes a phosphoror a quantum dot.

The scattering particle 144 scatters the excited light emitted from thelight excitation particle 142.

The reflection wall 146 reflects the excited light from the lightexcitation particle 142 and/or the excited light scattered by thescattering particle 144.

The light blocking pattern BM is disposed corresponding to boundaries ofa pixel area to block light. The light blocking pattern BM overlaps agate line (not shown) and a data line (not shown).

In the illustrated exemplary embodiment of FIG. 6, a plurality of lightexcitation particles 142 is distributed in a first depth area DA1 of thecolor conversion layer 147. A plurality of scattering particles 144 isdistributed in a second depth area DA2 of the color conversion layer147. The first depth area DA1 is positioned below the second depth areaDA2 within the color conversion layer 147.

When viewed cross-sectionally, the light blocking pattern BM has adesired depth D and a width. In the illustrated exemplary embodiment ofFIG. 6, an upper width UW of the light blocking pattern BM issubstantially the same as a lower width LW of the light blocking patternBM, but is not limited thereto or thereby.

The reflection wall 146 is adjacent to an outer surface or edge of thelight blocking pattern BM. In particular, for example, the lightblocking pattern BM may be disposed at an upper portion of the colorconversion layer 147, and the reflection wall 146 may be adjacent to alower surface of the light blocking pattern BM. The reflection wall 146may be disposed in a substantially perpendicular direction to the lowersurface of the light blocking pattern BM within the color conversionlayer 147.

FIG. 7 is a cross-sectional view of another exemplary embodiment of aPL-LCD device according to the invention.

Referring to FIG. 7, an exemplary embodiment of a PL-LCD device 300according to the invention includes a backlight unit 110 and aphotoluminescent panel 120 displaying an image in response to light fromthe backlight unit 110. The exemplary embodiment of the PL-LCD device300 according to the invention is substantially the same as the PL-LCDdevice 100 of FIG. 1 except that a plurality of light excitationparticles 142 and a plurality of scattering particles 144 areinterspersed with each other within a color conversion layer 147 incontrast to being disposed in substantially stratified depth layers.

The backlight unit 110 emits the light having a desired wavelength suchas ultraviolet waveband or blue light waveband toward thephotoluminescent panel 120. The backlight unit 110 includes a lightsource (not shown) generating and emitting the light having the desiredwavelength.

The photoluminescent panel 120 includes an array substrate 130, a facingsubstrate 140, and a liquid crystal layer 150 disposed between the arraysubstrate 130 and the facing substrate 140. The photoluminescent panel120 adjusts transmissivity of the light from the backlight unit 110 todisplay an image.

The array substrate 130 includes a first transparent substrate 131, aswitching element 133 disposed on a pixel area of the first transparentsubstrate 131, an insulation layer 135 partially exposing an electrodeof the switching element 133, and a pixel electrode 137 electricallyconnected to an output electrode of the switching element 133 anddisposed on the pixel area.

The facing substrate 140 includes a second transparent substrate 141, acommon electrode 143 disposed on a first surface of the secondtransparent substrate 141, a third transparent substrate 145 disposed onan opposing second surface of the second transparent substrate 141 andfacing the second transparent substrate 141, and a color conversionlayer 147 disposed between the second transparent substrate 141 and thethird transparent substrate 145. The facing substrate 140 may furtherinclude an intermediate layer 149 between the second transparentsubstrate 141 and the color conversion layer 147. The facing substrate140 may further include a polarizing film (not shown) between the secondtransparent substrate 141 and the color conversion layer 147.

The color conversion layer 147 includes a light excitation particle 142,a scattering particle 144 and a reflection wall 146. The lightexcitation particle 142, the scattering particle 144 and the reflectionwall 146 may be disposed within a resin layer. In one exemplaryembodiment, for example, the resin layer may include a silicon resin ora photoresist resin. The color conversion layer 147 may further includea light blocking pattern BM.

The light excitation particle 142 absorbs light having a desiredwavelength to have an excited state. From the excited state, the lightexcitation particle 142 returns to a ground state emitting some amountof light energy. The light excitation particle 142 includes a phosphoror a quantum dot.

The scattering particle 144 scatters the excited light emitted from thelight excitation particle 142.

The reflection wall 146 reflects the excited light from the lightexcitation particle 142 and/or the excited light scattered by thescattering particle 144.

The light blocking pattern BM is disposed corresponding to boundaries ofa pixel area to block light. The light blocking pattern BM overlaps agate line (not shown) and a data line (not shown).

In the illustrated exemplary embodiment of FIG. 7, a plurality of lightexcitation particles 142 and a plurality of scattering particles 144 areinterspersed with each other within the color conversion layer 147. Thatis, the light excitation particles 142 are distributed at both upper andlower portions of the color conversion layer 147. Likewise, thescattering particles 144 are distributed at both the upper and the lowerportions of the color conversion layer 147.

When viewed cross-sectionally, the light blocking pattern BM has adesired depth D and a width. In the illustrated exemplary embodiment ofFIG. 7, an upper width UW of the light blocking pattern BM issubstantially the same as a lower width LW of the light blocking patternBM, but is not limited thereto or thereby.

The reflection wall 146 is adjacent to an outer surface or edge of thelight blocking pattern BM. In particular, for example, the lightblocking pattern BM may be disposed at the upper portion of the colorconversion layer 147, and the reflection wall 146 may be adjacent to alower surface of the light blocking pattern BM. The reflection wall 146may be disposed in a substantially perpendicular direction to the lowersurface of the light blocking pattern BM within the color conversionlayer 147.

FIG. 8 is a cross-sectional view of another exemplary embodiment of aPL-LCD device according to the invention.

Referring to FIG. 8, an exemplary embodiment of a PL-LCD device 400according to the invention includes a backlight unit 110 and aphotoluminescent panel 120 displaying an image in response to light fromthe backlight unit 110. The exemplary embodiment of PL-LCD device 400according to the invention substantially the same as the PL-LCD device100 of FIG. 1 except for cross-sectional shapes of a light blockingpattern BM and a reflection wall 146 within a color conversion layer147. Hereinafter, detailed description of the identical elements isomitted.

The color conversion layer 147 of the photoluminescent panel 120includes a light excitation particle 142, a scattering particle 144 andthe reflection wall 146. The color conversion layer 147 may furtherinclude the light blocking pattern BM.

When viewed cross-sectionally, the light blocking pattern BM has anoverall desired depth D and widths within the color conversion layer147. An upper width UW of the light blocking pattern BM is substantiallydifferent from a lower width LW of the light blocking pattern BM. Asillustrated in the exemplary embodiment of FIG. 8, an upper width UW ofthe light blocking pattern BM such as defined by an upper portionthereof, is larger than the lower width LW such as defined by a lowerportion thereof. Also, the light blocking pattern BM has a curved orstepped side surface. In FIG. 8, for example, a difference in widths ofthe upper and lower portions of the light blocking pattern BM form astepped profile side surface in the cross-sectional view. Alternatively,a difference in the upper and lower widths UW and LW may transition moregradually to form a curved profile side surface. The upper and lowerportions of the light blocking pattern BM may be continuous with eachother, such as to form a single, unitary, indivisible light blockingpattern BM, but is not limited thereto or thereby.

A first portion of the reflection wall 146 is adjacent to the curved orstepped side surface of the light blocking pattern BM, and may have acorresponding profile to the side surface of the light blocking patternBM. A second portion of the reflection wall 146 connected and continuouswith the first portion is elongated in a substantially perpendiculardirection with respect to a lower surface of the light blocking patternBM. The first and second portions of the reflection wall 146 may form aunitary, indivisible reflection wall 146, but is not limited thereto orthereby.

The reflection wall 146 having the above-described cross-sectionalnon-linear shape reflects more of the excited light emitted the lightexcitation particle 142 near a boundary of a color area within the colorconversion layer 147.

FIG. 9 is a cross-sectional view of another exemplary embodiment of aPL-LCD device according to the invention.

Referring to FIG. 9, an exemplary embodiment of a PL-LCD device 500according to the invention includes a backlight unit 110 and aphotoluminescent panel 120 displaying an image in response to light fromthe backlight unit 110. The exemplary embodiment of the PL-LCD device500 according to the invention is substantially the same as the PL-LCDdevice 100 of FIG. 1 except for cross-sectional shapes of a lightblocking pattern BM and a reflection wall 146 within a color conversionlayer 147. Hereinafter, detailed description of the identical elementsis omitted.

The color conversion layer 147 of the photoluminescent panel 120includes a light excitation particle 142, a scattering particle 144 andthe reflection wall 146. The color conversion layer 147 may furtherinclude the light blocking pattern BM.

When viewed cross-sectionally, the light blocking pattern BM has adesired depth D and widths within the color conversion layer 147. Anupper width UW of the light blocking pattern BM is substantiallydifferent from a lower width LW of the light blocking pattern BM. Asillustrated in the exemplary embodiment of FIG. 9, the upper width UW ofthe light blocking pattern BM is narrower than the lower width LW of thelight blocking pattern BM. Also, the light blocking pattern BM has atilted or inclined side surface. The depth D of the light blockingpattern BM is substantially equal to or less than depth of the colorconversion layer 147. The inclined side surfaces and the substantiallyplanar upper and lower surfaces of the light blocking pattern BM definea trapezoidal cross-sectional shape.

The reflection wall 146 is adjacent to the side surface of the lightblocking pattern BM and has a corresponding tilted or inclined profile.Upper and/or lower surfaces of the light blocking pattern BM and thereflection wall 146 may be substantially coplanar with each other, butare not limited thereto or thereby.

The light blocking pattern BM having the trapezoidal cross-sectionalshape reflects more of the excited light emitted from the lightexcitation particle 142 near a boundary of a color area of the colorconversion layer 147.

FIG. 10 is a cross-sectional view of another exemplary embodiment of aPL-LCD device according to the invention.

Referring to FIG. 10, an exemplary embodiment of a PL-LCD device 600according to the invention includes a backlight unit 110 and aphotoluminescent panel 120 displaying an image in response to light fromthe backlight unit 110. The exemplary embodiment of the PL-LCD device600 according to the invention is substantially the same as the PL-LCDdevice 100 of FIG. 1 except for cross-sectional shapes of a lightblocking pattern BM and a reflection wall 146 within a color conversionlayer 147. Hereinafter, detailed description of the identical elementsis omitted.

The color conversion layer 147 of the photoluminescent panel 120includes a light excitation particle 142, a scattering particle 144 andthe reflection wall 146. The color conversion layer 147 may furtherinclude the light blocking pattern BM.

When viewed cross-sectionally, the light blocking pattern BM has adesired depth D and widths within the color conversion layer 147. Anupper width UW of the light blocking pattern BM is substantiallydifferent from a lower width LW of the light blocking pattern BM. Asillustrated in the exemplary embodiment of FIG. 10, the upper width UWof the light blocking pattern BM is wider than the lower width LW of thelight blocking pattern BM. Also, the light blocking pattern BM has atilted or inclined side surface. The depth D of the light blockingpattern BM is substantially equal to or less than depth of the colorconversion layer 147. The inclined side surfaces and the substantiallyplanar upper and lower surfaces of the light blocking pattern BM definea reverse trapezoidal cross-sectional shape.

The reflection wall 146 is adjacent to the side surface of the lightblocking pattern BM, and has a corresponding tilted or inclined profile.

The light blocking pattern BM having the reverse trapezoidalcross-sectional shape reflects more of the excited light emitted fromthe light excitation particle 142 near a boundary of a color area of thecolor conversion layer 147.

What is claimed is:
 1. A photoluminescent panel comprising: a lower substrate; an upper substrate facing the lower substrate and comprising a plurality of color areas spaced apart from each other by a gap therebetween; a liquid crystal layer between the lower substrate and the upper substrate; and a color conversion layer on the upper substrate, and comprising: a reflection wall provided in plural to define pairs of adjacent reflection walls among which first pairs of adjacent reflection walls define the color areas therebetween; and a flattening layer commonly disposed between each pair of adjacent reflection walls, the flattening layer comprising a base material layer in which a light excitation particle which absorbs light having a desired wavelength and emits excited light, and a scattering particle which scatters the excited light are distributed, wherein a same base material layer including a portion of the base material layer in which the light excitation particle is disposed extends from between the first pairs of adjacent reflection walls to be disposed at the gap between color areas.
 2. The photoluminescent panel of claim 1, wherein the color conversion layer further comprises a first area in which the light excitation particle is disposed and a second area in which the scattering particle is disposed, and the first area is above the second area.
 3. The photoluminescent panel of claim 1, wherein the color conversion layer further comprises a first area in which the light excitation particle is disposed and a second area in which the scattering particle is disposed, and the first area is below the second area.
 4. The photoluminescent panel of claim 1, wherein the flattening layer disposed in the color areas spaced apart from each other further comprises a plurality of light excitation particles and a plurality of scattering particles interspersed with each other therein.
 5. The photoluminescent panel of claim 1, wherein the color conversion layer further comprises a light blocking pattern, and the reflection wall is elongated in a substantially perpendicular direction with respect to a lower surface of the light blocking pattern.
 6. The photoluminescent panel of claim 5, wherein a cross-sectional side surface of the light blocking pattern has a curved or a stepped shape, the reflection wall contacts and covers the cross-sectional side surface of the light blocking pattern, and an end portion of the reflection wall is elongated in the substantially perpendicular direction with respect to the lower surface of the light blocking pattern.
 7. The photoluminescent panel of claim 5, wherein the light blocking pattern has a first width at an upper portion thereof and a second width at a lower portion thereof, and the first width is different from the second width.
 8. The photoluminescent panel of claim 7, wherein the light blocking pattern has a tilted cross-sectional side surface, and the reflection wall contacts and covers the tilted cross-sectional side surface of the light blocking pattern.
 9. The photoluminescent panel of claim 1, wherein the color conversion layer further comprises a plurality of light excitation particles emitting different color lights, the light excitation particles comprising at least two materials among a green phosphor, a red phosphor and a yellow phosphor.
 10. The photoluminescent panel of claim 1, wherein the color conversion layer further comprises a plurality of light excitation particles emitting different color lights, the light excitation particles comprising at least two materials among a green quantum dot, a red quantum dot and a blue quantum dot.
 11. The photoluminescent panel of claim 1, wherein the scattering particle comprises titanium oxide or silicon oxide.
 12. A photoluminescent liquid crystal display device comprising: a backlight unit which emits light having a desired wavelength; a first substrate on the backlight unit; a second substrate facing the first substrate and comprising a plurality of color areas spaced apart from each other by a gap therebetween; a liquid crystal layer between the first and the second substrates; and a color conversion layer on the second substrate, and comprising a reflection wall provided in plural to define pairs of adjacent reflection walls among which first pairs of adjacent reflection walls define the color areas therebetween; and a flattening layer commonly disposed between each pair of adjacent reflection walls, the flattening layer comprising a base material layer in which a light excitation particle which absorbs light having a desired wavelength and emits excited light, and a scattering particle which scatters the excited light are distributed, wherein a same base material layer including a portion of the base material layer in which the light excitation particle is disposed extends from between the first pairs of adjacent reflection walls to be disposed at the gap between color areas.
 13. The photoluminescent liquid crystal display device of claim 12, wherein the color conversion layer further comprises: a light blocking pattern which blocks the excited lights.
 14. The photoluminescent liquid crystal display device of claim 13, wherein the reflection wall is elongated in a substantially perpendicular direction with respect to a lower surface of the light blocking pattern.
 15. The photoluminescent liquid crystal display device of claim 12, further comprising an optical filter layer between the color conversion layer and the second substrate. 